1. Field of the Invention
The present invention relates to a foldable/deployable truss structure suitable for an antenna support structure or a platform support structure mounted in, e.g., a spacecraft.
2. Description of the Related Art
In a method proposed to construct a truss structure in the space, a folded structure is transported from the ground by a launch vehicle and deployed in the space. A conventional truss structure of this type is a two-dimensional structure called a deployable truss disclosed in Japanese Patent Disclosure (Kokai) No. 61-98699.
However, the shape and size of the above truss structure are limited in a deployed state due to its structural property. Therefore, if the assembly precision of the truss structure is degraded by a thermal deformation or various vibrations in the space, for example, the degraded precision cannot be corrected.
For this reason, it is proposed to mount a deformation correction mechanism for correcting the thermal deformation of the truss structure and maintaining desired assembly precision on the conventional truss structure.
However, if the deformation correction mechanism is added to the truss structure, the number of parts constituting the structure is increased, the structure is complicated, and the weight of the structure is increased.
In addition, in order to prevent vibrations produced in the truss structure, e.g., a resonance between a control system of the truss structure and the structure, it is proposed, like a conventional support structure of a solar array paddle, to increase the stiffness of the entire truss structure, adhere a damping material, or mount a vibration suppression mechanism.
However, among these methods, when the stiffness of the structure is increased, a sufficient damping effect cannot be obtained because the material of the structure is limited, and the weight is increased. When the damping material is adhered on the structure, a sufficient damping effect cannot be obtained if the structure is large. Furthermore, when the vibration suppressing mechanism is mounted on the structure, the number of parts of the structure is increased to increase the weight of the structure.
As described above, in order to put the conventional truss structure into practical use, a deformation correction mechanism or a protecting means against vibrations must be mounted on the structure. As a result, the structure of the entire truss structure is complicated so as to increase the weight of the structure.